Last summer, the university professor and former Rhodes scholar was in New York, having already earned a doctorate in public health at Oxford and a medical degree at Columbia. At 31, he was a rising star in the study of how social factors affect public health.

But then, as El-Sayed recalls it, he decided he wanted something more. He was tired of simply studying public health problems. He wanted to help solve them. “I think I want to be the health commissioner for Detroit,” he told a mentor.